1. Field of the Invention
The present invention relates generally to tape cassettes, such as, those intended for use in video tape recorders and other types of information processing apparatus, and more particularly is directed to improvements in the structures by which supply and take-up reels are positioned within the cassette housing.
2. Description of the Prior Art
As shown on FIGS. 1-3, a conventional tape cassette 1 for use in a video tape recorder (VTR) generally comprises a cassette housing or casing 2 formed by mutually connecting upper and lower housing portions 3 and 4, respectively, molded of a synthetic resin. The conventional tape cassette 1 further includes a front cover or lid 5, also molded of synthetic resin, and hingedly connected to the cassette housing 2 so as to be movable between opened and closed positions. A supply reel 6 and a take-up reel 7 are located within cassette housing 2, and a magnetic tape 9 is wound about reels 6 and 7 and extends therebetween. A cut-out portion 8 is provided at the front of cassette housing 2, and magnetic tape 9 extends from supply reel 6 about a tape guide 10a and then through an opening 11a to the exterior of housing 2 at one side of cut-out 8. From opening 11a, tape 9 extends across cut-out 8 past the front surface of a tape positioning member 12 located at the center of cut-out 8 and formed so as to position tape 9 between member 12 and cover or lid 5 when the latter is in its closed position. After extending across cut-out 8, magnetic tape 9 extends into housing 2 through an opening 11b at the side of cut-out 8 remote from opening 11a, whereupon the tape passes through a tape guide 10b and is wound on take-up reel 7. The upper housing portion 4 is conventionally formed with a rectangular transparent window 13 through which the amounts of tape 9 wound on reels 6 and 7, respectively, can be observed. Leaf springs 14 are mounted, at one end, at the underside of upper housing portion 4 and are engageable at their free ends, with central nipples 6b and 7b at the tops of supply reel 6 and take-up reel 7, respectively, for urging such reels toward lower housing portion 3. Thus, when tape cassette 1 is not in use, springs 14 maintain reels 6 and 7 against the bottom of housing 2, as particularly shown on FIG. 3, so as to ensure that an annular depending rim provided at the bottom of each of the reels, for example, as indicated at 6a in the case of the supply reel 6 on FIG. 3, remains loosely within a corresponding circular hole 3a in lower housing portion 3 for rotatably positioning the respective reel within the cassette housing.
When tape cassette 1 is loaded onto a video tape recorder (not shown) and operatively positioned, cover or lid 5 is opened, reels 6 and 7 are engaged by respective reel support spindles and thereby slightly lifted from the bottom of cassette housing against the force of leaf springs 14, magnetic tape 9 is drawn out of housing 2 and loaded about a guide drum, and then recording and/or reproducing of video or other signals is effected on the tape 9 by means of rotary magnetic heads associated with such guide drum.
In the illustrated tape cassette 1 according to the prior art, each of leaf springs 14 is fixed within housing 2 by means of a thermoplastic pin 15 depending from the undersurface of upper housing portion 4 and extending through a respective hole 14a formed in the mounted end portion of the leaf spring. After being extended through the respective hole 14a, the tip or free end portion of each pin 15 is heated or otherwise softened and then pressed or squeezed to form a laterally enlarged head 15a (FIG. 4) against the leaf spring 14 by which the latter is retained on the respective pin 15.
However, since the surfaces of each leaf spring 14 are relatively smooth, after the head 15a has been formed or molded on pin 15 for holding the leaf spring 14 thereon, there is the danger that the leaf spring may turn or wobble about the respective pin 15 and thereby risk disturbance of the desired secure engagement of the free end of the spring 14 with a nipple at the center of the top of the respective reel.